An explosion late Thursday at the Mexico City headquarters of the state-run Pemex oil company has killed 25 people and injured more than 100 others.
Rescuers are searching for people who may still be trapped in the smoldering tower. Helicopters, firefighters and emergency technicians are on the scene. Some of the people injured in the blast were being rolled away on gurneys, while others were pushed out on rolling office chairs.
Video from the Mexican capital showed debris covering the ground and smoke streaming from the lower floors of the scorched building.
There is no word yet on what caused the blast, but officials say equipment problems in the basement may have been responsible.
Mexican President Enrique Pena Nieto visited the site of the blast late Thursday, issued his condolences to the families of the victims, and said he has ordered an investigation.
In September, a huge explosion at a Pemex plant near the city of Reynosa killed 30 people.
In 2010, a Pemex oil pipeline exploded in the central town of San Martin Texmelucan, killing 29.